Electron-discharge device and method of operating the same



Jul 20 1926. 1,593,373

H. J. VAN DER BIJL ELECTRON DISCHARGE DEVICE AND METHOD OF OPERATING THE SAME Filed July 20. 1920 Fig.

Hehar/k L/. van der 51/]1 re atta July 20,1926;

UNITED] s r'Aras PATENT omen.

nan-Dam JOHANNES or: BIJL, NEW YORK, N. 1., ASSIGNOR TO WESTERN ELEG- TBIC CODA, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW TOE-I.

ELEOTBON-DTSOHAEGE DEVICE AND METHOD OF OPERATIE'G THE SAME.

Application fled my so, 1920. Serial No. 897,771.

This invention relates to electron discharge devices which are ada tedto be employed for repeating or amp 'fying electric 1m ulses and for similar purposes.

6 object of the invention is to provide a device of the above described type and a method of operating the same in which the discharge current changes rapidly with small changes of voltage through a certain 1 range of applied voltage.

-A further object of the invention is to provide a discharge device in which an insulated charge derived from the discharge current is employed for controlling the discharge.

A further object of the invention is to provide an improved means for utilizing a dischar e of secondary electrons.

It has amen found that when a highly evacuated tube containing an anode and a source of electrons or cathode'is provided with a narrow tubular portion between the anode and the cathode that no current can be passed through the tube up to a relatively high voltage.

- cumulation of a ne ative charge of electrons on the wall 0 the narrow tube. In one tube in which the tubular portion was about one-half inch in diameter, no current flowed until the a li dt g was about 500 volts. The current thensuddenly jumped to about two milliamperes;

This was accompanied by a slight fluorescence on the walls of the tubular portion, indicating that secondary electrons were being produoedvby bombardment of the wall and part of the energy of the electrons being converted into visible radiation- At higher voltages, the discharge behaved as a pure electron discharge, showing that it was independent of gas ionization. The amount of ionization of the glass walls, on which the current depends, is very.

greatly influenced by external magnetic or electrostatic fields. A relatively small magnetic field transverse to the axis of the tube may be sufficient to stop the discharge altogether. Electric impulses which are passed through the winding of an electromagnet arranged in this or other positions adjacent the narrow tube may be repeated in amplified iorm in the electrode circuit of the device.

Herein are disclosed two amplifier cir- This is due to the accuits embodying the invention each employing magnetic input circuits, but it is obvious that devices of this type may be controlled by other ma etic means or by electrostatic means, an that they ma be utilized in circuits other than amp 'fier circuits, for example, oscillation generator circuits. For the latter purpose they are of advantage over three electrode tubes in that secondary emission from the third electrode is avoided.

Further objects of the invention will a pear as pointed out in the following escription and appending claims.

In the drawings, Fig. 1 re resents diagrammaticall a circuit embo ying the'invention in w ichthe controlling magnetic field has its axis transverse to the axis of the tube; Fig. 2 is similar to Fig. 1, but shows the magnetic axis coinciding with the axis of the tube. I

An evacuated tube 10 of glass or other suitable material is highly evacuated and has its internal parts as thoroughly denuded of occluded gas as possible. Within the tube 10 are a cathode 11 shown in the form of a thermionic filament, and an anode 12. These electrodes are connected externally through the source of current 15.

The end portions of the tube 10 are connected by a narrow tubular portion 16. When volta up to a certain value are applied to t e electrodes, electrons emitted by. cathode 11 adhere to the walls or the narrow portion 16 and form a negative charge sufiicient to return other electrons to the cathode. When, however, the applied voltage is increased beyond a ,point which may be termed the critical voltage, the current suddenly increases to a relatively large value and the fluorescence above referred to appears, indicating that the current is carried at least in part by electrons secondarily emitted by ionization of the walls.

For utilizing the device as an amplifier, electromagnet 18 is placed so that its axis is transverse to the narrow portion 16 and its winding is connected in series with the secondary of transformer 20, the primary of which ma be connected to a source of impulses to e amplified. The electrode circuit contains the primary of a'transformer 22 which may be connected to a "ran ed to tra electrons assin g lly P in rent flow between said electrodes,

circuit or device for utilizing the amplified im ulses.

ig. 2 is similar to Fig. 1 except that the magnetic winding 25 of the input circuit is wound on the tubular ortion 16. The discharge current may a so be controlled by this arran ement.

In the operation 0 this device as an amplifier, a potential difference is impressed between the electrodes 11 and 12 sufficient to overcome the blocking eflect incidentto the collection of a negative charge on the tube 16, thus allowing a limited current flow between said electrodes. The strength of the blocking charge on the restricted portion 16 is under the control of the field of the electromagnet 18 and is varied in ac cordance with electric undulations supplied thereto. As slight changes .in the field strength of the electromagnet 18 vary materially the strength of the blocking charge in the tube 16, the undulations impressed upon electroma et 18 result in am lified undulations in t 0 output circuit of t e device.

What is claimed is:

1. In an electric translating device a vacuum tube comprising a vessel composed of insulating material, a cathode and anode therein, said vessel having a restricted portion between said anode and cathode artherethrough norma to establish a ocking charge, means for impressing between said anode and cathode a sufficient potential to overcome said charge and establish a curan input circuit, and means for controlling the strength of the blocking charge in said restricted portion in accordance with electric undulations impressed on said input circuit.

2. In an electric translating device a vac- "x uum tube comprising a vessel composed of insulating material, a cathode and an anode therein, said vacuum tube having a restricted port-ion between said cathode and anode arranged to trap electrons passing therethrough normally to establish a blocking char e, means for impressing between said ano e and cathode a sufficient potential to overcome said charge and establish a current flow between said electrodes, an in.- put circuit, and electromagnetic means in said input circuit for varying the strength of said blocking charge in accordance with electric undulations impressed on said input circuit.

3. In an electric translating device a vac uum tube comprising a vessel composed of insulating material, a cathode and an anode therein, said vessel havin a restricted portion between said catho e and anode arranged to trap electrons passin therethrough normally to establish a locking charge, means to impress a sufficient potential between said electrodes to overcome said blocking charge and establish a current flow between said electrodes, an in ut circuit, and means in said input circuit or producing a magnetic field 1n the vicinity of said restricted portion whereby the strengthof said blocking charge is varied in accordance with electric undulations impressed upon said input circuit.

4. In an electric translating device a vacuum tube comprising a vessel composed of insulating material, a cathode and an anode therein, said vessel l1avin a restricted portion between said cathode and anode arranged to tra electrons passln' therethrough normally to establish a locking charge, means for impressing between said anode and cathode a sufiicient potential to overcome said charge and establish a current flow between said electrodes, an electromagnet having its axis at rignt angles to said restricted portion, and means for in1- pressing electric undulations upon the field winding of said ma net to vary the strength of said blocking cfiarge.

5. In an electric translating device an electron discharge device having a narrow passage in the discharge ath of a character to acquire a charge blocking the discharge current through a range of applied voltages, means for applying a voltage suiliclent to overcome the blocking eifect of said charge and establish a current flow between said electrodes, an input circuit, means in said input circuit for establishing an electromagnetic field in the vicinity of said passage, and means for impressing electric undulations on said input circuit.

In witness whereof, I hereunto subscribe my name this 13th da of July, A. 1)., 1920.

ES van DER BIJL.

HENDRI JOHAN. 

